Emerson's Fieldbus Technology Used to Upgrade Temp Monitoring at Largest UK Coal Fired Power Station

Emerson's Fieldbus Technology Used to Upgrade Temp Monitoring at Largest UK Coal Fired Power Station

May 152006

AUSTIN, TEXAS (May 15, 2006) -- Emerson Process Management has supplied FOUNDATION fieldbus based Rosemount® temperature transmitters and interface units to transmit data from over 500 temperature monitoring points on one of the boiler and turbine systems at Drax Power Station, the largest, cleanest and most efficient coal fired power station in the UK. The Emerson solution was chosen by Drax Power and Capula, the contractor undertaking the refurbishment, following presentations and demonstrations of interfacing the Rosemount 3420 fieldbus interface module to their Schneider PLC host system.

Drax Power Station uses six steam boilers to generate up to 4000MW. At current output levels Drax supplies enough power to meet 7% of UK demand. The main fuel used is pulverized coal, but Drax Power has developed the capability to burn alternative fuels such as biomass to blend and burn with the coal. The temperature sensors are mainly thermocouples used for monitoring the boiler tubes, superheater and re-heater, plus turbine and generator temperatures in high density arrangements, to detect any irregularities or hot spots.

The monitoring thermocouples are linked individually to one of the 70 Rosemount 848T eight-input temperature transmitters supplied on this project. The ambient temperature specification (up to +85ºC) of the 848T units allows them to operate accurately in the existing cabinets located in the high-temperature environment around the boiler. Up to 13 of the Rosemount 848T units can be powered from one FOUNDATION fieldbus segment, transmitting the temperature measurements from up to 104 sensors along two wires.

The link between the site fieldbus segments and the host PLC system is provided by seven Rosemount 3420 fieldbus interface modules: that each power up to four separate FOUNDATION fieldbus segments and retransmit the data over a Modbus RS485 serial connection. The Rosemount 3420 unit also provides an Ethernet port for separate connection of a supervisory PC, which can be used to configure the unit as needed - for example when a sensor is changed. It also allows access to the diagnostic data available over the fieldbus to monitor the sensor and transmitter performance.

While providing Drax Power with a neat and accurate system solution, the extra capabilities of the Rosemount 3420 will allow further investigation of any unusual heat patterns during tests of alternative fuels and firing systems. It will also reduce the complexity and time needed for the rewiring task on the current retrofit. Once installed, the availability of FOUNDATION fieldbus segments around the boiler will allow the addition of further test equipment or other sensors for plant condition monitoring, with relatively simple configuration to transmit the data back to the supervisory systems, and no extra wiring.

About Emerson Process ManagementEmerson Process Management (www.EmersonProcess.com), an Emerson business, is a leader in helping businesses automate their production, processing and distribution in the chemical, oil and gas, refining, pharmaceutical, food and beverage, pulp and paper, power and other industries. A division of Emerson, Rosemount (www.EmersonProcess.com/Rosemount) is a global leader in high-precision pressure, temperature, level, and flow instrumentation.

About EmersonEmerson is a global leader in bringing technology and engineering together to provide innovative solutions to customers through its network power, process management, industrial automation, climate technologies, and appliance and tools businesses. Sales in fiscal 2004 were $15.6 billion. For more information, visit www.GoToEmerson.com.